Underworld
by SpaghettiToastBook

This mod generates an underworld deep underground (Y = -25000 and below by default). Portals can be crafted to enter
and exit the underworld more easily. The underworld is very dangerous, but contains high concentrations of valuable
minerals.

Settings:
    underworld_depth: The underworld is generated under this Y value. (Default: -25000)
    underworld_barrier_size: This many layers of obsidian will separate the underworld from the world above. (Default: 20)

Dependencies:
    default

Optional dependencies:
    meseportals
    mobs_monster
    moreores
    stairs (highly recommended!)
    technic
    tnt (highly recommended!)

License for code: CC0
Licenses for art:
    CC-BY-SA 3.0:
        underworld_stone.png (derivative of default_stone.png, by cisoun)
        underworld_brick.png (derivative of default_stone.png, by cisoun)
    CC0:
        Everything else